The present invention relates to a method for securely joining two parts which extend at least essentially parallel to one another along a common section, and more particularly for fixedly joining the mutually facing edges of a clamping or compression ring as well as to the product made with such method.
For clamping fast tubularly shaped elements on a corresponding peripheral area of a cylindrical formed part such as, for example, of a shaft or of a further tubular member, so-called clamping rings are used in a known manner.
The use of clamping rings with so-called ears, which, as such, has proved very successful in practice, is not suited under certain conditions, especially, for example, when space conditions do not permit any projecting ears.
In those cases, so-called clamping or compression rings have been used, which, for purposes of clamping, are either externally shrunk or pressed together over the connection or which press the two tubularly shaped members against one another by expansion of the cylindrically shaped formed part.
Such clamps or compression rings are manufactured in that ring-like segments are sawed off, punched off or cut off from pipes having the required diameter. However, this type of manufacture has proved disadvantageous, and more particularly because
(a) the newly made pipes have to be deburred along their outer longitudinal sides of the ring which requires a further operating step,
(b) only stainless materials can be used, for example, no galvanized pipes, because the rings are damaged along the longitudinal sides, i.e., the galvanization is missing and because
(c) only one ring size can be made with one pipe diameter.
A further possibility consists in bending up so-called washers whereby large forces have to be applied for this operation and additionally large internal stresses are present in the ring part. Also, rings with any desired diameter cannot be made with a certain size of a washer.
A further possibility would consist in the manufacture of a ring from a corresponding band-like part which had been cut-off from an endless band, by a ring-shaped bending of the cut-off part. However, it has been found that the connection of the two end portions of the band represent a weak point and that this connection does not withstand in particular loads in tension and compression.
It is therefore an object of the present invention to provide an arrangement for the connection of such mutually facing terminal band edges for the manufacture of a ring, in particular, and an arrangement for the connection of two edges in general which can be stressed in particular in tension and compression.
The underlying problems are solved according to the present invention by at least one retaining element at one edge which form-lockingly engages from behind, as viewed in the edge direction, in a recess provided in the other edge, and by at least one projection at the one edge laterally offset with respect to the element, which abuts form-lockingly essentially in the edge direction at the part with the recess.
The present invention proposes an arrangement for connecting two edges at flat areal parts extending essentially parallel to one another at least along a common section, which includes at least one retaining element at one edge that form-lockingly engages from behind, as viewed in the edge direction, in a recess provided in the other edge, and which further includes at least one projection at the one edge laterally offset with respect to the element, as viewed in the transverse direction in which the retaining element engages the recess from behind, whereby the projection(s) form-lockingly abuts or abut at the part with the recess essentially in the edge direction.
It is further proposed according to a modification of the present invention that the retaining element engages the recess from behind, as viewed in the edge direction, on both sides thereof and that correspondingly on both sides of the element one projection each laterally offset is arranged at the one edge which form-lockingly abuts in the edge direction at the part with the recess, as viewed in the direction toward the element.
Especially during the connection of two edges along a relatively short section, it is proposed according to this invention that the retaining element engages the recess from behind essentially in the center of the common section and that the projection or the projections is or are arranged essentially in the area or areas of an end or of the ends of the section.
For an arrangement for connecting two band-like longitudinally extending parts along terminal edges arranged essentially transversely to the band direction, whereby the band widths of the parts are preferably nearly equal at least within the area of the terminal edges, a retaining element is proposed according to the present invention at the one edge which form-lockingly engages from behind, as viewed in the edge direction, in a recess having a shape essentially congruent or complementary to the element and at least one projection at the one edge is proposed laterally offset with respect to the element, as viewed in the direction of the engagement from behind, which form-lockingly abuts at the part with the recess essentially in the edge direction.
In a further modified embodiment, it is proposed according to the present invention to arrange a retaining tongue essentially in the center of the one edge having lugs or lobes protruding on both sides of the tongue essentially parallel to the edge direction, which form-lockingly engages from behind an essentially congruent recess in the other edge also arranged essentially centrally, and to further arrange one projection each laterally offset on both sides of the tongue in the one edge, preferably end-face at the one edge, whereby each projection form-lockingly abuts at the band-like part with the recess essentially parallel to the edge direction each in a direction toward the recess.
The connection of relatively narrow band-like parts along their terminal edges is also possible by means of this modification.
However, if the two parts involve plates which are connected along a longitudinally extending common section, then the connection preferably includes two retaining elements at the one edge, whereby preferably one retaining element each is arranged in one-half of the common section. Analogous to the above-described embodiments, the at least two retaining elements engage form-lockingly from behind, as viewed in the edge direction in corresponding recesses provided in the other edge, and at least one projection each is arranged at the one edge laterally offset to the outermost element in the direction toward the end of the common section which form-lockingly abuts at the part with the recesses essentially in the edge direction against the respective outermost recess.
In order to securely fix the above-described connections, it is further proposed in accordance with the present invention that the connection includes at least one punching, rivet-like cold deformation and/or spot-welded place along the common section of the edges, of the retaining element and/or of the projection.
The described arrangements for the connection in accordance with the present invention are suited in particular for the manufacture of clamps consisting of at least one open clamping band with terminal edges arranged at its ends transversely to the band direction.
Preferably such a clamp includes a one-piece clamping band whereby the two end-face terminal edges are connected with each other by means of an arrangement according to the present invention.
Such a clamp is suited in particular for the manufacture of a pipe clamp or of a compression ring.
Furthermore, a method for the connection of two edges of flat parts is proposed according to the present invention which extend at least essentially parallel to one another at least along a common section.
According to this method, at least one retaining element is provided at one edge which is introduced form-lockingly engaging from behind in the edge direction in a corresponding recess provided in the other edge in order to prevent a pulling out of the element out of the recess and therewith to hold the parts at one another. In order to prevent that the portion engaged from behind in the part provided with the recess is bent-out to open up the recess, at least one projection is arranged at the one edge laterally offset in the direction of the engagement from behind with respect to the element, which form-lockingly abuts essentially in the edge direction at the part with the recess in such a manner as to counteract the force component acting away from the recess essentially in the edge direction and resulting during compression and/or tensional load of the connection by reason of the engagement from behind of the recess by the element. A bending out of the aforementioned portions which are engaged from behind is effectively prevented thereby.
According to a preferred method for the connection of two band-like, longitudinally extending parts along terminal edges arranged essentially transversely to the band direction, in which the band width of the parts are preferably nearly equal at least within the area of the terminal edges, it is proposed according to the present invention that a retaining tongue be arranged essentially in the center of the one edge which includes essentially parallel to the edge direction on both sides thereof, one projecting lug or lobe each, and in that the tongue is introduced form-lockingly engaging from behind in an essentially congruent recess arranged also essentially in the center in the other edge. One projection each is arranged in the one edge laterally offset on both sides of the tongue which form-lockingly abuts at the respective band-like part having the recess in the direction toward the recess and essentially parallel to the edge direction. The lateral bending out of the two portions of the band-like part having the recess which are disposed laterally of the tongue and are engaged from behind, is effectively counteracted by these two projections whereby the thus-produced connection can be stressed in tension and compression.
In order to further strengthen or fix the connection, the edges are punched, cold-deformed rivet-like or spot-welded together at least at one place of the common section, of the retaining tongue and/or of the projection.
The described methods according to the present invention are suited in particular for the connection of one or several band-like parts for the manufacture of a clamp or of a clamping ring.
With the use of a clamping or compression ring made in such a manner, a method for the connection of a cylindrical formed part or of a tubular part with at least one further tubular element or with a bellows is proposed, in which the further tubular element or the bellows is slipped or placed over a peripheral area of the formed part or of the one tubular member and subsequently a clamp or compression ring according to the present invention is slipped or placed over the further tubular element or bellows in the emplaced or slipped-over area. Finally, either the clamping ring is shrunk or compressed by means of suitable tools or the one formed part or the one tubular member is radially outwardly expanded in the peripheral area.